BIO-201L Topic 4: Terms List - Joints and Muscle Tissue

Identify the basic structure of articulations.

What is an articulation? What are the components of an articulation?

Articulation: A joint where bones meet

3 Types of Joints

1.     Synarthrosis – No movement

2.     Amphiarthrosis – Slightly moveable joint

3.     Diarthrosis – Freely moveable joint

Types of joints:

            Synostosis: Totally ridged, immovable joint created when two bones fuse and the boundary between them disappears

Sutures: Found in the skull, immovable and held together by dense fibrous connective tissue

Gomphoses: Peg in socket fibrous joints

                        Syndesmoses: Bones are connected by ligaments, allows for slight movement

Synchondroses: Bones are joined by hyaline cartilage, immoveable

Symphyses: Bones are joined by fibrocartilage, provides strength and flexibility

            Synovial: Joints are fluid filled synovial cavity, allows for wide range of motion

Identify the structures of a synovial joint.

Articular capsule: Covers the ends of bones, reducing friction and absorbing shock

Synovial cavity: Lubricates the joint, reducing friction and allowing for smooth movement

Synovial fluid: The fluid inside a joint

-       3 Functions: Lubrication, Distribution of Nutrients, Shock Absorption

Articular cartilages: Covers the articulating surfaces of bone, helps reduce friction

Menisci: Fibrocartilage between 2 bones

Fat pads: Adipose tissue usually superficial to the joint capsule

Bursae: Small fluid filled pouches by joints – helps to reduce friction and act as a shock absorber

Tendon sheath: A layer of synovial membrane that wraps around a tendon

Identify the structures of selected joints. Identify the type of joint and important features.

Intervertebral discs

            Anulus fibrosus: Tough outer layer of fibrocartilage, Surrounds the nucleus pulposus

            Nucleus pulposus: Gelatinous core, helps with shock absorption and reduces compressive loads

            Protruding disc: When the disc bulges out but the outer layer isn’t broken

            Herniated disc: Nucleus pulposus herniates or breaks through the annulus fibers

Shoulder joint

            Glenoid labrum: Fibrocartilage that fills the glenoid cavity, increases surface area and creates a larger socket

            Coraco-acromial ligament: Supports the shoulder from above

            Acromioclavicular ligament: Connects the acromion and clavicle

            Coracoclavicular ligament: Provides stability between coracoid process and clavicle

Elbow joint

            Annular ligament: Binds the radius to the ulna, this allows radius to rotate

            Radial collateral ligament: Stabilizes the lateral side of the elbow

            Ulnar collateral ligament: Stabilizes the medial side of the elbow

Hip joint

            Acetabular labrum: Increases joint cavity depth

Ligamentum teres: Connects the femur head with the acetabulum

            Pubofemoral ligament: Limits excessive extension and abduction

            Ischiofemoral ligament: Helps prevent hyperextension

            Iliofemoral ligament: Strongest ligament, prevents hyperextension

Knee joint

            Patellar ligament: Connects kneecap to tibia

            Quadriceps tendon: Connects muscles to kneecap

            Lateral collateral ligament LCL: Stabilize the lateral side of the joint

            Medial collateral ligament MCL: Stabilize the medial side of the joint

            Medial meniscus: Cushion and stabilizer

            Lateral meniscus: Cushion and stabilizer

            Anterior cruciate ligament ACL: Anterior surface of the tibia, resists anterior tibial translation

            Posterior cruciate ligament PCL: Posterior surface of the tibia, resists posterior translation

Describe the general functions of the muscular system.

Name the six functions of skeletal muscle. (We will cover cardiac and smooth later.)

1.     Produce Skeletal Movement

2.     Maintain Posture and Body Position

3.     Support Soft Tissues

4.     Guard Body Entrances and Exits

5.     Maintain Body Temperature

6.     Store Nutrients

Describe and understand the basic function of muscle contractions.

Muscle contraction is the tightening, shortening, or lengthening of muscles when you do some activity. As organs that contain cells that can contract, muscles can generate force and movement. Skeletal muscle works in conjunction with the bones of the skeleton to create body movements

Identify the different types of muscle tissue at the microscopic level. (Striation, fiber organization, location of nucleus)

Skeletal muscle:

-       Striation: Yes

-       Fiber Organization: Long, cylindrical fibers

-       Location of nucleus: Multinucleated 

Cardiac muscle:

-       Striation: Yes

-       Fiber Organization: Branched fibers interconnected at junctions

-       Location of nucleus: One centrally located nucleus

            Intercalated disc: Connects cardiac muscle cells to assist with contraction as a single organ

Smooth muscle:

-       Striation: No

-       Fiber Organization: Spindle shaped fibers

-       Location of nucleus: Single central nucleus